1. Field of the Invention
The present invention relates to a three-dimensional game apparatus which can synthesize a filed image from any view in a virtual three-dimensional space, and an image synthesizing method usable in such a three-dimensional game apparatus.
2. Description of the Prior Art
In many game systems, various proposals have been made to create a so-called virtual game world in a displayed game scene which has been more similar to real life. If such a virtual world is realized, fun of the game can be extremely improved and reality of the game world increased.
To accomplish the virtual world, it is desired that the concept of time is introduced into the game world.
A two-dimensional game system in which a two-dimensional game scene is displayed on a display or the like can give a passage of time to a player, for example, by taking such a technique that the daytime game scene is brightened while the nighttime game scene is darkened. Such a technique may provide a plurality of pallets for forming the game scene. For the daytime game scene, a pallet for providing a brighter color to the game scene is selected. For the nighttime game scene, another pallet for providing a darker color to the game scene is selected. However, this technique can only select either the brighter or darker game scene. Thus, the prior art cannot represent the sun which moves with the passage of time, the changing color of the sky or the gradually darkening background in the nighttime game scene. Therefore, the game systems of the prior art represents the game world with less reality.
In a combat game, for example, players select game characters 230 and 232 as shown in FIG. 20A, respectively. The players then control the actions of the game characters 230 and 232 for causing them to fight each other while viewing such a game scene as shown in FIG. 20B. In this case, the type of the displayed game stage depends on the type of the selected game character or the like. If a competitor or the like belongs to a country A, for example, a game stage may include buildings 234 in a country-A design and an audience 236 of the country A. This can provide a sense in which a player actually fights the competitor in the country A. If the player defeats the competitor of the country A, the game proceeds to the next game stage. In the next game stage, the player then fights another competitor of a country B. This stage is in a country-B style. Thus, the game sequentially proceeds to the other game stages as the player defeats the competitors.
In such a game apparatus having a plurality of game stages, a game stage presents a nighttime scene while another game stage presents a daytime scene. In the same game stage, the setting of time will not be changed. This will cause the game to lack variety.
Even though the passage of time can be presented in the same game stage, the start of that game stage may be in nighttime or daytime. Similarly, the game stage lacks variety.
In many arcade game machines, a demo scene is frequently displayed while no player plays the game. One technical object would be to give more variety to such a demo scene.
It is now considered the presentation of various heavenly bodies such as moon and stars on a game scene in the combat game or the like. In such a case, it is relatively easy that these heavenly bodies appear in the nighttime and disappear in the daytime. However, it is very difficult to present a game scene in which the heavenly bodies gradually appear as the sky becomes dark and gradually disappear as the sky becomes bright. An object of the prior art would be to provide a simple technique for such a presentation of a game scene.
To overcome the problems in the prior art, the present invention has an object to provide a three-dimensional game apparatus in which a player can sense the passage of time and to provide an image synthesizing method usable in such a three-dimensional game apparatus.
Another object of the present invention is to provide a three-dimensional game apparatus in which a game scene represented at each game stage was variety, and to provide an image synthesizing method usable in such a three-dimensional game apparatus.
Still another object of the present invention is to provide a three-dimensional game apparatus which can represent the passage of time when a game is not played, and to provide an image synthesizing method usable in such a three-dimensional game apparatus.
A further object of the present invention is to provide a three-dimensional game apparatus which can provide objects which gradually disappear or appear as the brightness of the game scene varies through the passage of time, and to provide an image synthesizing method usable in such a three-dimensional game apparatus.